EA Deliverable: Architecture Strategy: Enterprise Computing (sample)

A single computer system, such as the mainframe, is like a ship -- a complete system of complex interacting elements. Guiding and running a ship is one challenge. Guiding and controlling a fleet of ships is a challenge on a different level. It requires structure as well as good design for each ship. Multiple computers are like a fleet of ships. The network of computers must work within a structure or framework. If the network of computers includes many different (“heterogeneous”) types, the challenge is much greater. It is a difficult challenge to make them work together.

Client/server architecture provides the foundation on which to build the enterprise computing strategy. This section will cover:

· Involving users directly in the design and development to ensure maximum usability and effectiveness.

For ABCModel2 Company, it is imperative that they be able to purchase enterprise applications. The technical architecture must support this. Therefore, the architecture must be flexible enough to enable this. However, there is a seeming paradox in that the architecture must adopt standards to meet the challenges posed by management. The standards may decrease the flexibility in one dimension (limit the buying options), while increasing flexibility in another dimension (empowering the users to access consistent reliable data).

Whenever possible, the Enterprise-Wide Architecture Strategy will adopt the following standards bodies’ recommendations:

Open Systems Interconnection (OSI),

Open System Foundation’s (OSF) technical architecture where appropriate, and

X/OPEN where appropriate.

In addition, ABCModel2 Company will be required to integrate systems provided by many vendors, while at the same time supporting the small business units within the operating companies. This requires simplifying the technical components as much as possible (see IS drivers in the Business Model).

The architecture will meet the IS drivers and the objectives put forth in this document.

While the business challenges IS to provide more flexible reliable systems that focus on user and business needs, the client/server architecture is more complex than the traditional centralized architecture now employed at ABCModel2 Company.

Enterprise-Wide Applications deployed on a distributed computing infrastructure change the basic assumptions made when developing applications. Previously, a host-based application:

Performed one set of functions

Had a simple interface (3270 or terminal)

One or more programs handled the integration of functions, or the system did not integrate the functions

A distributed application must:

Work with distributed services

Perform a wide range of integrated functions

Provide a Graphical User Interface (GUI)

Gone is the highly structure 3270 interface. The pre-defined navigational path through the forms to the database is non-existent in a client/server architecture. The GUI is freeform, and the program may access data from a multitude of sources.

Developing and deploying applications to run in this environment is challenging. The applications must accommodate a variety of hardware, operating systems, network protocols, databases, and services. However, the performance (processor speed and user response) and reliability of the client/server applications must meet, and in many cases, exceed that expected on the mainframe.

Some of the requirements of client/server applications today are:

High Performance

Portability

Reliability

Transparency -- Interoperability and Integration

Scalability

Manageability

The IS drivers documented in the business model capture most of these requirements. The following sections of this document discuss how the Enterprise-Wide Application Architecture offers a solution from the technical perspective.

Client/server systems involve multiple desktops, servers, and infrastructure items. The architecture addresses these issues, but the reader must nevertheless understand the complexities. IS will be required to:

Decide on how to allocate applications and data across client and servers. (This is not part of the EWAS project, but the project will continue to note the requirement.)

Program the user interface and client logic. (The project will continue to encourage the team to separate the business logic from the client. The discipline required to do this is understood by all; however, the industry has documented the reasons for doing this. The team understands the problems of portability and maintenance for large client/server applications when the business logic is on the client.)

Build interfaces to one or more relational database systems.

Build and maintain application modules for each different platform or environment.

Plan, design, and implement the communication protocols required for data access and synchronization. (The reader must remember that business transactions must be synchronized and guarantee data integrity across environments.)

Build integration to heritage systems on the mainframe and other platforms.

Maintain and enhance multiple versions for different platforms.

Plan, Design and Implement System and Network Management.

Traditional tools and architectures may help, but they still require ABCModel2 Company to piece together various components of the applications with low level code. Tools like Powerbuilder continue to make this easier once the infrastructure is in place. However, as previously stated, ABCModel2 Company must struggle to provide the correct infrastructure.

The EWAS project is about solving these requirements, and simplifying the environment as much as possible. It involves:

enabling easy access to computing and data resources,

protecting the value of ABCModel2 Company’s existing applications, while allowing IS to move the applications to client/server as business needs require, and

enabling the users to gain the benefits of the new technologies.

The EWAS team developed the technical architecture while continuing to stress open and flexible architectures for different business requirements.

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